in this experiment, the acceleration due to gravity is related to the time t it takes ball to fall a

in this experiment, the acceleration due to gravity is related to the time t it takes ball to fall a distance y by g=(2y)/(t^2). With this equation and (delta W/W)=(((((n(delta a))/a)^2)+((m (delta b)/b)^2)+(((p(delta c))/c)^2)^1/2), show that the fractional error delta g/g is (((((delta y)/y)^2)+(((2 delta t)/t)^2))^(1/2)